A Conditional Random Field is a class of statistical modelling method often applied in pattern recognition and machine learning, where they are used for structured prediction.
From Wikipedia ... "CRFs are a type of discriminative undirected probabilistic graphical model. It is used to encode known relationships between observations and construct consistent interpretations. It is often used for labeling or parsing of sequential data, such as natural language text or biological sequences and in computer vision. Specifically, CRFs find applications in shallow parsing, named entity recognition and gene finding, among other tasks, being an alternative to the related hidden Markov models. In computer vision, CRFs are often used for object recognition and image segmentation"
